SILENT SAVINGS; Vue hybrid eschews fanfare en route to fuel economy.(News)

Byline: KEVIN A. WILSON

Those who believe driving a hybrid is all about "green'' bragging rights might overlook the inconspicuous Saturn Vue Green Line, but if saving money and reducing fuel consumption are your primary aims, that would be too bad. We recently drove a Vue Green Line on a short loop of mixed city streets and highways near General Motors' Powertrain engineering facilities in Pontiac, Michigan, and found it promises a lot for the mainstream customer who needs to combine utility, an affordable sticker and reasonable fuel economy.

On sale in August, the electrically assisted four-cylinder, front-drive sport/utility won't thrill technophiles or hard-core environmentalists. Here's why: Rather than integrating complex, expensive and heavy hardware into the transmission as is done with "full'' hybrids from Toyota, Honda and Ford, the Vue is the first application for GM's "belt alternator starter'' system (it appears later in the 2007 Chevrolet Malibu and Saturn Aura). While simpler than other hybrids, it goes beyond the stop-restart system that drew criticism when GM called it a hybrid in its full-size pickup.

Using regenerative braking to charge an NiMH battery pack housed beneath the cargo floor at the front of the spare-tire well, the alternator/starter motor can power the vehicle for very brief periods. It takes some pretty sophisticated electronics, but mechanically it's just a robust motor connected to the engine crankshaft via a toothed belt, with a unique two-way tensioner that allows it to operate either as a generator or as a motor. Mostly, it provides assist when the driver calls for ...